# JSON: a text format for data

[Concepts explained](README.md)

**JSON** stands for *JavaScript Object Notation*. It is a way to write structured data as text so different programs can exchange it. You do not need to learn JavaScript to read a small JSON document.

## Read a player card

This is JSON data, not a Pliro program:

```json
{"name": "Mila", "score": 12, "badges": ["starter"], "ready": true}
```

The braces group named values. `"score"` is a key and `12` is its value. The square brackets contain a list. JSON calls the brace-shaped group an **object** and the list an **array**.

JSON has text, numbers, true/false values, arrays, objects, and `null` for no value. Keys use double-quoted text. JSON does not allow comments or trailing commas. These rules come from the [JSON standard](https://www.rfc-editor.org/rfc/rfc8259).

## In Pliro storage

A Pliro map looks similar but follows Pliro's own rules. Pliro uses `none` where JSON uses `null`; Dutch Pliro uses `geen`, `waar`, and `onwaar`. JSON's words stay unchanged in Dutch.

Pliro's saved-data functions accept JSON-compatible values. That means values that can be represented using these data kinds. Functions cannot be saved as JSON. The storage layer handles the conversion; you pass ordinary Pliro values to `saveData`.

You do not need to assemble JSON strings to save a score. Read [saving data](../guides/storage.md) for the supported calls and limits. This article does not introduce a JSON parsing built-in.

Try reading the card aloud: what is the value of `ready`, and how many badges are listed?